capillary: Quick Facts

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Photos and Videos

Illustration of a capillary cross section showing red blood cells moving from an artery to a vein. Arrows indicate oxygen and nutrients leaving the blood to enter body cells, while carbon dioxide and wastes enter the blood from body cells.

gas exchange in the lung

Diagram of the circulatory system showing a red artery carrying blood from the heart, branching into smaller arterioles and capillaries, then merging into blue venules and a vein returning blood to the heart.

Diagram showing the anatomy of the small intestine with labeled regions (duodenum, jejunum, ileum), a cross-section highlighting muscle and mucosa layers, an enlargement of mucosal folds (plicae circulares), and a detailed view of a villus structure with epithelial, goblet, endocrine, and Paneth cells, microvilli, blood capillaries, and lacteal.

Watch red blood cells travel through arteries and capillaries to deliver oxygen

Function of red blood cells explained

Understanding the human cardiovascular system

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Topics

blood-brain barrier human cardiovascular system vein artery purpura Osler-Rendu-Weber disease blood vessel sinusoid blood pressure

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Key People

Marcello Malpighi

Marcello Malpighi

Italian scientist

August Krogh

August Krogh

Danish physiologist

Male muscle, man flexing arm, bicep curl.

Facts You Should Know: The Human Body Quiz